The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Internal combustion engines combust an air and fuel mixture within cylinders to drive pistons, which produces drive torque. Air flow into gasoline engines may be regulated via a throttle. The throttle may adjust throttle area, which increases or decreases air flow into the engine. As the throttle area increases, the air flow into the engine increases.
A fuel control system controls the rate that liquefied petroleum gas (LPG) is supplied to the engine to provide a desired air/LPG mixture to the cylinders. Increasing the amount of air and LPG provided to the cylinders generally increases the torque output of the engine.
Before being provided to the engine, the LPG is stored in an LPG tank. An LPG pump draws LPG from the LPG tank and pressurizes the LPG in a fuel rail. Fuel injectors provide LPG to the engine from the fuel rail. In some engine systems, the LPG pump operates at a maximum duty cycle (DC) at all times during vehicle operation to ensure that the LPG is sufficiently pressurized in the fuel rail to maintain the LPG in the liquid form.